Climate Trivia: Arctic and Antarctica
Over the past century, the Arctic was cooler than normal from 1900-1915, warmer than normal during the 20′s, 30′s and 40′s, cooler than normal during the 50′s, 60′s and 70′s and has been warmer than normal from the early 1980′s to today.
Trivia Question: During warm periods in the Arctic, is the Antarctic generally:
a) Also warmer than normal
b) In an opposite cool phase
c) Antarctic temperatures were steady over the 20th century
d) No positive or negative relationship between Arctic and Antarctic temperatures exist
The correct answer is b. Periods when the Arctic is warmer than normal tend to be periods when Antarctica is cooler than normal and vice-versa. This “bipolar seesaw” phenomenon has been linked to well-documented shifts in ocean circulation, specifically the 65-70 year Atlantic Multidecadal Oscillation. Strong winds around Antarctica bring salty waters from the ocean depths to the surface. These waters are heated by the sun and Atlantic surface currents take the warm and salty waters North. When this process is at its most efficient, more warm water is transported to the far north, warming the Arctic and cooling the Antarctic. When the process is not efficient, more warm water stays around Antarctica, warming that continent instead of the Arctic. This general pattern has been observed in long-term (millennial) paleo-ice core records. The last 30 years have been different, however, with a dramatically warmer Arctic without a corresponding cooling of the Antarctic.
Seasons: Winter, Spring, Summer, Fall
Source: Chylek, P et al. “Twentieth century bipolar seesaw of the Arctic and Antarctic surface air temperatures.” Geophysical Research Letters 37 (2010): L08703.
